CN109319819B - A kind of technology for preparing 6N grade strontium nitrate - Google Patents

Abstract

The present invention is a process for preparing 6N-level strontium nitrate. The 2N-level strontium nitrate solution is used as a feed solution and C272 is used as an extractant to extract and separate and remove the impurity elements chlorine, sulfur, sodium, potassium, beryllium and magnesium in the 2N-level strontium nitrate solution. , calcium, barium, lead, zinc, aluminum and iron, etc., to prepare 6N grade strontium nitrate solution. Specifically, it consists of five steps: saponification section, fractional extraction and separation of ClSNaKBeMgCaSr/SrBaPbZnAlFe, full-load quasi-fractionated extraction and separation of ClSNaKBeMgCa/Sr, fractional extraction and separation of Sr/BaPbZnAlFe and stripping section. In the prepared 6N-grade nitric acid solution, the purity of strontium is 99.9991%-99.9998%, and the yield is 92%-96%. The invention has the characteristics of high product purity and yield, less reagent consumption, high separation efficiency, short process flow, low production cost and the like.

Description

A kind of technology for preparing 6N grade strontium nitrate

technical field

The invention relates to a process for preparing 6N-grade strontium nitrate, which involves using 2N-grade strontium nitrate solution as feed liquid and C272 as extractant to extract and separate chlorine, sulfur, sodium, potassium, beryllium, magnesium, calcium, barium, lead, Zinc, aluminum, iron and other impurities to prepare 6N grade strontium nitrate solution. The specific technical field of the present invention is the preparation of 6N grade strontium nitrate.

Background technique

The increase in the impurity content in the material usually rapidly reduces the function and properties of the material, and the adverse effect of impurities on high-end materials and high-purity materials is more pronounced. 6N grade (99.99990%～99.99998%) strontium nitrate is not only an important high-purity strontium product, but also one of the basic substances for preparing 6N-grade strontium carbonate and other ultra-high-purity strontium products. Therefore, it is of great strategic significance to develop a technology for preparing 6N-grade strontium nitrate.

The metal element impurities and non-metal impurities in the strontium nitrate enrichment solution are separated and removed by separation techniques such as precipitation, and a 2N-grade strontium nitrate solution can be obtained; finally, a 2N-grade strontium nitrate crystal is obtained by concentrating and crystallization. As of today, there is no technical method for further purifying and preparing 6N-grade strontium nitrate using 2N-grade strontium nitrate as a raw material. The technical methods based on precipitation and crystallization (precipitation-reprecipitation, crystallization-recrystallization) are used to separate impurities in the feed liquid, and the purity of the final separated products are all lower than 6N (the purity of most of the separated products is 3N). There is no doubt that it is impossible to prepare 6N grade strontium nitrate based on the precipitation-crystallization technique.

At present, there is no method for preparing 6N-grade strontium nitrate using 2N-grade strontium nitrate as a raw material. As far as the preparation of 6N grade strontium nitrate is concerned, the technical difficulty lies in the separation and removal of the alkaline earth metal impurities in the 2N grade strontium nitrate solution. Aiming at the key technical problems and technical difficulties existing in the preparation of 6N-grade strontium nitrate, the present invention establishes a method for rapidly, simply and efficiently separating impurities such as magnesium, calcium, and barium in 2N-grade strontium nitrate solution, and prepares 6N-grade strontium nitrate. solution.

SUMMARY OF THE INVENTION

A process for preparing 6N-grade strontium nitrate in the present invention provides a method for directly preparing 6N-grade strontium nitrate by using a 2N-grade strontium nitrate solution as a feed liquid, aiming at the existing technology for preparing 6N-grade strontium nitrate and the technical difficulties of preparing 6N-grade strontium nitrate .

A process for preparing 6N grade strontium nitrate in the present invention uses 2N grade strontium nitrate solution as feed liquid, bis(2,4,4-trimethylpentyl)phosphonic acid (abbreviated as C272 or Cyanex272) as extractant, and extracts, separates and removes Impurity elements chlorine, sulfur, sodium, potassium, beryllium, magnesium, calcium, barium, lead, zinc, aluminum and iron in 2N grade strontium nitrate solution; prepare 6N grade strontium nitrate solution.

A process for preparing 6N-grade strontium nitrate in the present invention consists of 5 steps, wherein 1 saponification section, 3 separation sections and 1 stripping section. The 5 steps are respectively saponification section, fractional extraction and separation of ClSNaKBeMgCaSr/SrBaPbZnAlFe, full-load quasi-fractionated extraction and separation of ClSNaKBeMgCa/Sr, fractional extraction and separation of Sr/BaPbZnAlFe and stripping section. Among them: the extraction section of fractional distillation extraction and separation of ClSNaKBeMgCaSr/SrBaPbZnAlFe realizes the separation of ClSNaKBeMgCaSr/BaPbZnAlFe, and the washing section realizes the separation of ClSNaKBeMgCa/SrBaPbZnAlFe. Full-load quasi-fractionation extraction and separation of ClSNaKBeMgCa/Sr, fractional distillation and extraction and separation of Sr/BaPbZnAlFe are directly connected in series; the outlet organic phase of full-load quasi-fractionation extraction and separation of ClSNaKBeMgCa/Sr directly enters the first stage of fractional extraction and separation of Sr/BaPbZnAlFe, and fractional extraction and separation of Sr/BaPbZnAlFe. The first-stage outlet aqueous phase is used as a detergent for the extraction and separation of ClSNaKBeMgCa/Sr by full-load quasi-fractionation.

The 5 steps of a kind of technique for preparing 6N grade strontium nitrate of the present invention are as follows:

Step 1: Saponification Section

Step 1 is the saponification section to realize the strontium saponification of the C272 organic phase. According to the molar ratio of C272: ammonia water: strontium = 1: 0.36: 0.18, the C272 organic phase, 6.0 mol/L ammonia water and the ClSNaKBeMgCaSr/SrBaPbZnAlFe from step 2 were fractionated and extracted and the first-stage outlet water phase containing chlorine, sulfur , Strontium nitrate solution of sodium, potassium, beryllium, magnesium and calcium is added to the first stage of the saponification tank. After 8-stage co-flow saponification and phase separation, the water phase is saponification wastewater, the organic phase is strontium saponified C272 organic phase, and the saponification rate is 0.36. The obtained strontium saponified C272 organic phase is used as the extraction organic phase of step 2 for fractional distillation extraction and separation of ClSNaKBeMgCaSr/SrBaPbZnAlFe and step 3 for full-load quasi-fractionation extraction and separation of ClSNaKBeMgCa/Sr.

Step 2: Fractional extraction and separation of ClSNaKBeMgCaSr/SrBaPbZnAlFe

Step 2 is to separate ClSNaKBeMgCaSr/SrBaPbZnAlFe by fractional distillation, the extraction section realizes the separation of strontium and barium, lead, zinc, aluminum, iron and other impurity elements, and the washing section realizes the separation of strontium and chlorine, sulfur, chlorine, sulfur, sodium, potassium, beryllium, magnesium , calcium and other impurity elements separation. The organic phase of strontium saponification C272 was used as the extraction organic phase, the 2N grade strontium nitrate solution was used as the feed solution, and 3.0 mol/L HNO ₃ was used as the washing acid. The organic phase of strontium saponified C272 enters the ClSNaKBeMgCaSr/SrBaPbZnAlFe fractionation extraction system from the first stage, the 2N-stage strontium nitrate solution enters the ClSNaKBeMgCaSr/SrBaPbZnAlFe fractional distillation extraction system from the feed stage, and the 3.0mol/L HNO ₃ washing acid enters the ClSNaKBeMgCaSr/SrBaPbZnAlFe from the last stage. Fractional extraction system. The strontium nitrate solution containing Cl, S, Na, K, Be, Mg and Ca was obtained from the first-stage outlet water phase of the ClSNaKBeMgCaSr/SrBaPbZnAlFe fractional distillation extraction system, which was used as the feed liquid for the full-load quasi-fractionation extraction and separation of ClSNaKBeMgCa/Sr in step 3; The organic phase loaded with strontium, barium, lead, zinc, aluminum and iron is obtained from the organic phase at the last stage of the ClSNaKBeMgCaSr/SrBaPbZnAlFe fractional distillation extraction system, which is used as the feed liquid for the fractional extraction and separation of Sr/BaPbZnAlFe in step 4.

Step 3: Full-load quasi-fractionation extraction and separation of ClSNaKBeMgCa/Sr

Step 3 is full-load quasi-fractionation extraction and separation of ClSNaKBeMgCa/Sr, to realize the separation of strontium and chlorine, sulfur, sodium, potassium, beryllium, magnesium, calcium and other impurity elements. Taking the strontium saponified C272 organic phase as the extraction organic phase, the first-stage outlet aqueous phase of the ClSNaKBeMgCaSr/SrBaPbZnAlFe fractional extraction system in step 2 obtains a strontium nitrate solution containing Cl, S, Na, K, Be, Mg and Ca as the feed liquid, In step 4, the first-stage outlet water phase 6N-grade strontium nitrate solution of the Sr/BaPbZnAlFe is fractionated and extracted as a detergent. The strontium saponified C272 organic phase enters the ClSNaKBeMgCa/Sr fractionation extraction system from the first stage, the strontium nitrate solution containing Cl, S, Na, K, Be, Mg and Ca enters the ClSNaKBeMgCa/Sr fractionation extraction system from the feed stage, and 6N grade nitric acid The strontium solution enters the ClSNaKBeMgCa/Sr fractionation extraction system from the last stage. Aqueous nitrate solution containing chlorine, sulfur, sodium, potassium, beryllium, magnesium and calcium was obtained from the first-stage outlet aqueous phase of the ClSNaKBeMgCa/Sr fractionation extraction system for the recovery of valuable elements; The strontium-loaded C272 organic phase is obtained from the first-stage outlet organic phase, which is used as the extraction organic phase for the fractional distillation extraction and separation of Sr/BaPbZnAlFe in step 4.

Step 4: Fractional extraction and separation of Sr/BaPbZnAlFe

Step 4 is to separate Sr/BaPbZnAlFe by fractional distillation, so as to realize the separation of strontium and barium, lead, zinc, aluminum, iron and other impurities. Taking the strontium-loaded C272 organic phase obtained from the last stage of the ClSNaKBeMgCa/Sr fractional distillation extraction system in step 3 as the extraction organic phase, and the loaded strontium barium lead zinc aluminum iron obtained in the last stage of the ClSNaKBeMgCaSr/SrBaPbZnAlFe fractional distillation extraction system in step 2 The organic phase is the feed liquid, and 3.0mol/L HNO ₃ is used to wash the acid. The strontium-loaded C272 organic phase enters the Sr/BaPbZnAlFe fractional extraction system from the first stage, the strontium-barium-lead-zinc-aluminum-iron organic phase enters the Sr/BaPbZnAlFe fractional extraction system from the feed stage, and 3.0mol/L HNO ₃ washing acid is extracted from the last 1 into the Sr/BaPbZnAlFe fractional distillation extraction system. The target product 6N grade strontium nitrate solution was obtained from the first-stage outlet aqueous phase of the Sr/BaPbZnAlFe fractional distillation and extraction system; the C272 organic phase loaded with barium, lead, zinc, aluminum and iron was obtained from the last first-stage outlet organic phase of the Sr/BaPbZnAlFe fractional distillation and extraction system. Go to step 5 stripping section.

Step 5: Stripping section

The barium, lead, zinc, aluminum and iron supported in the C272 organic phase are back-extracted to the aqueous phase to realize the regeneration of the C272 organic phase. The C272 organic phase loaded with barium, lead, zinc, aluminum and iron obtained from the last stage of the Sr/BaPbZnAlFe fractional distillation extraction system in step 4 enters the stripping tank from the first stage, and the _3.6mol /L HNO solution enters the stripping tank from the 12th stage. . From the first-stage outlet water phase of the stripping section, a solution containing barium, lead, zinc, aluminum and iron is obtained for the recovery of valuable elements such as lead, cadmium and zinc; the organic phase is exported from the 12th stage of the stripping section , to obtain a regenerated C272 organic phase.

The C272 organic phase is a sulfonated kerosene solution of C272, wherein the concentration of C272 is 1.0 mol/L.

The relevant element concentrations in the 2N grade strontium nitrate solution are: C10.0010 g/L～0.0050g/L, S0.0010 g/L～0.010g/L, Na0.010 g/L～0.030g/L L, K0.0010 g/L～0.0050g/L, Be0.010 g/L～0.020g/L, Mg 0.010g/L～0.050g/L, Ca0.050 g/L～0.30g/L, Sr110 .0g/L～150.0g/L, Ba0.050g/L～0.20g/L, Pb0.0010g/L～0.0050g/L, Zn0.0010g/L～0.0050g/L, Al0.010g/L ～0.030g/L, Fe 0.010g/L～0.030g/L.

The relevant element concentrations in the 6N grade strontium nitrate solution are: C10.0000010g/L～0.0000050g/L, S0.0000010g/L～0.0000020g/L, Na0.0000010g/L～0.0000030g/L, K0 .0000010g/L～0.0000050g/L, Be0.0000020g/L～0.0000080g/L, Mg0.0000040g/L～0.000010g/L, Ca0.0000050g/L～0.000020g/L, Sr130.0 g/L～ 140.0g/L, Ba0.0000050g/L～0.000020g/L, Pb0.0000030g/L～0.000010g/L, Zn0.0000010g/L～0.000010g/L, Al0.0000010g/L～0.0000050g/L, Fe 0.0000010g/L～0.0000050g/L.

The beneficial effects of the present invention are as follows: 1) A material basis is laid for preparing 6N-grade strontium products: based on extraction technology, a method for preparing 6N-grade strontium nitrate solution is established. Moreover, the 6N-grade strontium nitrate solution can be obtained by post-processing such as concentrated crystallization or precipitation, and a series of 6N-grade strontium-containing compounds such as 6N-grade strontium nitrate crystals and 6N-grade strontium carbonate crystals can be obtained. 2) High product purity and high strontium yield: the target product 6N grade strontium nitrate solution has a purity of 99.99991% to 99.99998%, and a strontium yield of 92% to 96%. 3) Less reagent consumption: full-load quasi-fractionation extraction and separation of ClSNaKBeMgCa/Sr does not consume washing acid and stripping acid; fractional distillation extraction and separation of Sr/BaPbZnAlFe does not consume saponification alkali (ammonia). 4) High separation efficiency: 3 separation sections (fractional extraction and separation of ClSNaKBeMgCaSr/SrBaPbZnAlFe, full-load quasi-fractionated extraction and separation of ClSNaKBeMgCa/Sr, and fractional distillation and extraction of Sr/BaPbZnAlFe) separated and removed the sodium, potassium, beryllium, More than 10 kinds of metal impurities such as magnesium, calcium, barium, lead, zinc, aluminum, iron, etc., and non-metallic impurities such as chlorine, sulfur, silicon, and phosphorus. 5) Short technological process: the method for preparing 6N-grade strontium nitrate consists of 5 steps, including 1 saponification section, 3 separation sections and 1 stripping section. Fractional extraction and separation of ClSNaKBeMgCaSr/SrBaPbZnAlFe without stripping section. Fractional extraction and separation of ClSNaKBeMgCaSr/SrBaPbZnAlFe and full-load quasi-fractionated extraction and separation of ClSNaKBeMgCa/Sr share a saponification section. 6) Low production cost: high separation efficiency, short process flow, and saving consumption of saponification alkali (ammonia), washing acid (nitric acid) and stripping acid (nitric acid).

Description of drawings

Fig. 1 is the schematic flow sheet of inventing a kind of technique of preparing 6N grade strontium nitrate;

In the figure: LOP means loaded organic phase; W means detergent.

Detailed ways

A process for preparing 6N grade strontium nitrate of the present invention will be further described below in conjunction with specific embodiments.

Example 1

The organic phase of C272 is a sulfonated kerosene solution of C272, wherein the concentration of C272 is 1.0 mol/L.

The relevant element concentrations in the 2N grade strontium nitrate solution are: C10.0030 g/L, S0.0050 g/L, Na0.020g/L, K0.0030 g/L, Be0.015 g/L, Mg0.030 g/L, Ca0.20 g/L, Sr130.0 g/L, Ba0.10 g/L, Pb0.0030 g/L, Zn0.0030 g/L, Al0.020 g/L, Fe 0.020g/ L.

Step 1: Saponification Section

According to the molar ratio of C272: ammonia water: strontium = 1: 0.36: 0.18, the C272 organic phase, 6.0 mol/L ammonia water and the ClSNaKBeMgCaSr/SrBaPbZnAlFe from step 2 were fractionated and extracted and the first-stage outlet water phase containing chlorine, sulfur , Strontium nitrate solution of sodium, potassium, beryllium, magnesium and calcium is added to the first stage of the saponification tank. After 8-stage co-flow saponification and phase separation, the water phase is saponification wastewater, the organic phase is strontium saponified C272 organic phase, and the saponification rate is 0.36. The obtained strontium saponified C272 organic phase is used as the extraction organic phase of step 2 for fractional distillation extraction and separation of ClSNaKBeMgCaSr/SrBaPbZnAlFe and step 3 for full-load quasi-fractionation extraction and separation of ClSNaKBeMgCa/Sr.

Step 2: Fractional extraction and separation of ClSNaKBeMgCaSr/SrBaPbZnAlFe

The organic phase of strontium saponification C272 was used as the extraction organic phase, the 2N grade strontium nitrate solution was used as the feed solution, and 3.0 mol/L HNO ₃ was used as the washing acid. The organic phase of strontium saponified C272 enters the ClSNaKBeMgCaSr/SrBaPbZnAlFe fractionation extraction system from the first stage, the 2N-grade strontium nitrate solution enters the ClSNaKBeMgCaSr/SrBaPbZnAlFe fractional distillation extraction system from the 34th stage, and the 3.0mol/L HNO ₃ washing acid enters the ClSNaKBeMgCaSr/SrBaPbZnAlFe system from the 72nd stage Fractional extraction system. The strontium nitrate solution containing Cl, S, Na, K, Be, Mg and Ca was obtained from the first-stage outlet water phase of the ClSNaKBeMgCaSr/SrBaPbZnAlFe fractional distillation extraction system, which was used as the feed liquid for the full-load quasi-fractionation extraction and separation of ClSNaKBeMgCa/Sr in step 3; The organic phase loaded with strontium, barium, lead, zinc, aluminum and iron is obtained from the organic phase at the 72nd stage of the ClSNaKBeMgCaSr/SrBaPbZnAlFe fractional distillation extraction system, which is used as the feed liquid for the fractional extraction and separation of Sr/BaPbZnAlFe in step 4.

Step 3: Full-load quasi-fractionation extraction and separation of ClSNaKBeMgCa/Sr

Taking the strontium saponified C272 organic phase as the extraction organic phase, the first-stage outlet aqueous phase of the ClSNaKBeMgCaSr/SrBaPbZnAlFe fractional extraction system in step 2 obtains a strontium nitrate solution containing Cl, S, Na, K, Be, Mg and Ca as the feed liquid, In step 4, the first-stage outlet water phase 6N-grade strontium nitrate solution of the Sr/BaPbZnAlFe is fractionated and extracted as a detergent. The organic phase of strontium saponification C272 enters the ClSNaKBeMgCa/Sr fractionation extraction system from the 1st stage, the strontium nitrate solution containing Cl, S, Na, K, Be, Mg and Ca enters the ClSNaKBeMgCa/Sr fractionation extraction system from the 16th stage, and the 6N grade nitric acid The strontium solution enters the ClSNaKBeMgCa/Sr fractionation extraction system from the 58th stage. Aqueous nitrate solution containing chlorine, sulfur, sodium, potassium, beryllium, magnesium and calcium was obtained from the first-stage outlet aqueous phase of the ClSNaKBeMgCa/Sr fractionation extraction system for the recovery of valuable elements; from the first stage of the ClSNaKBeMgCa/Sr fractional distillation extraction system The 58-stage outlet organic phase obtains the strontium-loaded C272 organic phase, which is used as the extraction organic phase for the fractional distillation extraction and separation of Sr/BaPbZnAlFe in step 4.

Step 4: Fractional extraction and separation of Sr/BaPbZnAlFe

Taking the strontium-loaded C272 organic phase obtained from the last stage of the ClSNaKBeMgCa/Sr fractional distillation extraction system in step 3 as the extraction organic phase, and the loaded strontium barium lead zinc aluminum iron obtained in the last stage of the ClSNaKBeMgCaSr/SrBaPbZnAlFe fractional distillation extraction system in step 2 The organic phase is the feed liquid, and 3.0mol/L HNO ₃ is used to wash the acid. The organic phase of C272 loaded with strontium enters the Sr/BaPbZnAlFe fractional distillation and extraction system from the first stage, the organic phase loaded with strontium, barium, lead, zinc, aluminum and iron enters the Sr/BaPbZnAlFe fractional distillation and extraction system from the 44th stage, and 3.0mol/L HNO ₃ washing acid is extracted from the 78th stage. into the Sr/BaPbZnAlFe fractional distillation extraction system. The target product 6N grade strontium nitrate solution was obtained from the first-stage outlet aqueous phase of the Sr/BaPbZnAlFe fractional distillation and extraction system; the C272 organic phase loaded with barium, lead, zinc, aluminum and iron was obtained from the 78th outlet organic phase of the Sr/BaPbZnAlFe fractional distillation and extraction system. Go to step 5 stripping section.

Step 5: Stripping section

The C272 organic phase loaded with barium, lead, zinc, aluminum and iron obtained from the last stage of the Sr/BaPbZnAlFe fractional distillation extraction system in step 4 enters the stripping tank from the first stage, and the _3.6mol /L HNO solution enters the stripping tank from the 12th stage. . From the first-stage outlet water phase of the stripping section, a solution containing barium, lead, zinc, aluminum and iron is obtained for the recovery of valuable elements such as lead, cadmium and zinc; the organic phase is exported from the 12th stage of the stripping section , to obtain a regenerated C272 organic phase.

The relevant element concentrations in the target product 6N grade strontium nitrate solution are: C10.0000030g/L, S0.0000010g/L, Na0.0000020g/L, K0.0000030g/L, Be0.0000050g/L, Mg0.0000070g/L , Ca0.000010g/L, Sr135.0 g/L, Ba0.000010g/L, Pb0.0000050g/L, Zn0.0000300g/L, Al0.0000020g/L, Fe 0.0000020g/L. The product purity of the strontium nitrate solution is 99.99995%, and the yield of strontium is 94%.

Example 2

The organic phase of C272 is a sulfonated kerosene solution of C272, wherein the concentration of C272 is 1.0 mol/L.

The relevant element concentrations in 2N grade strontium nitrate solution are: C10.0010 g/L, S0.0010 g/L, Na0.010g/L, K0.0010 g/L, Be0.010 g/L, Mg 0.010g /L, Ca0.050 g/L, Sr150.0 g/L, Ba0.050 g/L, Pb0.0010 g/L, Zn0.0010 g/L, Al0.010 g/L, Fe 0.010g/L .

Step 1: Saponification Section

According to the molar ratio of C272: ammonia water: strontium = 1: 0.36: 0.18, the C272 organic phase, 6.0 mol/L ammonia water and the ClSNaKBeMgCaSr/SrBaPbZnAlFe from step 2 were fractionated and extracted and the first-stage outlet water phase containing chlorine, sulfur , Strontium nitrate solution of sodium, potassium, beryllium, magnesium and calcium is added to the first stage of the saponification tank. After 8-stage co-flow saponification and phase separation, the water phase is saponification wastewater, the organic phase is strontium saponified C272 organic phase, and the saponification rate is 0.36. The obtained strontium saponified C272 organic phase is used as the extraction organic phase of step 2 for fractional distillation extraction and separation of ClSNaKBeMgCaSr/SrBaPbZnAlFe and step 3 for full-load quasi-fractionation extraction and separation of ClSNaKBeMgCa/Sr.

Step 2: Fractional extraction and separation of ClSNaKBeMgCaSr/SrBaPbZnAlFe

The organic phase of strontium saponification C272 was used as the extraction organic phase, the 2N grade strontium nitrate solution was used as the feed solution, and 3.0 mol/L HNO ₃ was used as the washing acid. The strontium saponified C272 organic phase enters the ClSNaKBeMgCaSr/SrBaPbZnAlFe fractionation extraction system from the first stage, the 2N-grade strontium nitrate solution enters the ClSNaKBeMgCaSr/SrBaPbZnAlFe fractional distillation extraction system from the 30th stage, and the 3.0mol/L HNO ₃ washing acid enters the 64th stage into the ClSNaKBeMgCaSr/SrBaPbZnAlFe system Fractional extraction system. The strontium nitrate solution containing Cl, S, Na, K, Be, Mg and Ca was obtained from the first-stage outlet water phase of the ClSNaKBeMgCaSr/SrBaPbZnAlFe fractional distillation extraction system, which was used as the feed liquid for the full-load quasi-fractionation extraction and separation of ClSNaKBeMgCa/Sr in step 3; The organic phase loaded with strontium, barium, lead, zinc, aluminum and iron is obtained from the organic phase at the 64th stage of the ClSNaKBeMgCaSr/SrBaPbZnAlFe fractional distillation extraction system, which is used as the feed liquid for the fractional extraction and separation of Sr/BaPbZnAlFe in step 4.

Step 3: Full-load quasi-fractionation extraction and separation of ClSNaKBeMgCa/Sr

Taking the strontium saponified C272 organic phase as the extraction organic phase, the first-stage outlet aqueous phase of the ClSNaKBeMgCaSr/SrBaPbZnAlFe fractional extraction system in step 2 obtains a strontium nitrate solution containing Cl, S, Na, K, Be, Mg and Ca as the feed liquid, In step 4, the first-stage outlet water phase 6N-grade strontium nitrate solution of the Sr/BaPbZnAlFe is fractionated and extracted as a detergent. The strontium saponified C272 organic phase enters the ClSNaKBeMgCa/Sr fractionation extraction system from the 1st stage, the strontium nitrate solution containing Cl, S, Na, K, Be, Mg and Ca enters the ClSNaKBeMgCa/Sr fractionation extraction system from the 18th stage, and the 6N grade nitric acid The strontium solution enters the ClSNaKBeMgCa/Sr fractionation extraction system from the 56th stage. Aqueous nitrate solution containing chlorine, sulfur, sodium, potassium, beryllium, magnesium and calcium was obtained from the first-stage outlet aqueous phase of the ClSNaKBeMgCa/Sr fractionation extraction system for the recovery of valuable elements; from the first stage of the ClSNaKBeMgCa/Sr fractional distillation extraction system The 56-stage outlet organic phase obtains the strontium-loaded C272 organic phase, which is used as the extraction organic phase for the fractional distillation extraction and separation of Sr/BaPbZnAlFe in step 4.

Step 4: Fractional extraction and separation of Sr/BaPbZnAlFe

Taking the strontium-loaded C272 organic phase obtained from the last stage of the ClSNaKBeMgCa/Sr fractional distillation extraction system in step 3 as the extraction organic phase, and the loaded strontium barium lead zinc aluminum iron obtained in the last stage of the ClSNaKBeMgCaSr/SrBaPbZnAlFe fractional distillation extraction system in step 2 The organic phase is the feed liquid, and 3.0mol/L HNO ₃ is used to wash the acid. The organic phase of C272 loaded with strontium enters the Sr/BaPbZnAlFe fractional extraction system from the first stage, the organic phase loaded with strontium, barium, lead, zinc, aluminum and iron enters the Sr/BaPbZnAlFe fractional extraction system from the 40th stage, and the 3.0mol/L HNO ₃ washing acid is extracted from the 78th stage. into the Sr/BaPbZnAlFe fractional distillation extraction system. The target product 6N grade strontium nitrate solution was obtained from the first-stage outlet aqueous phase of the Sr/BaPbZnAlFe fractional distillation and extraction system; the C272 organic phase loaded with barium, lead, zinc, aluminum and iron was obtained from the 74th outlet organic phase of the Sr/BaPbZnAlFe fractional distillation and extraction system. Go to step 5 stripping section.

Step 5: Stripping section

The C272 organic phase loaded with barium, lead, zinc, aluminum and iron obtained from the last stage of the Sr/BaPbZnAlFe fractional distillation extraction system in step 4 enters the stripping tank from the first stage, and the _3.6mol /L HNO solution enters the stripping tank from the 12th stage. . From the first-stage outlet water phase of the stripping section, a solution containing barium, lead, zinc, aluminum and iron is obtained for the recovery of valuable elements such as lead, cadmium and zinc; the organic phase is exported from the 12th stage of the stripping section , to obtain a regenerated C272 organic phase.

The relevant element concentrations in the target product 6N grade strontium nitrate solution are: C10.0000010g/L, S0.0000010g/L, Na0.0000010g/L, K0.0000010g/L, Be0.0000020g/L, Mg0.0000040g/L , Ca0.0000050g/L, Sr140.0 g/L, Ba0.0000050g/L, Pb0.0000030g/L, Zn0.0000010g/L, Al0.0000010g/L, Fe 0.0000010g/L. The product purity of the strontium nitrate solution is 99.99998%, and the yield of strontium is 96%.

Example 3

The organic phase of C272 is a sulfonated kerosene solution of C272, wherein the concentration of C272 is 1.0 mol/L.

The relevant element concentrations in the 2N grade strontium nitrate solution are: C10.0050 g/L, S 0.010g/L, Na0.030g/L, K 0.0050g/L, Be0.020 g/L, Mg0.050 g/L L, Ca0.30 g/L, Sr110.0 g/L, Ba0.20 g/L, Pb0.0050 g/L, Zn0.0050 g/L, Al0.030 g/L, Fe0.030 g/L .

Step 1: Saponification Section

According to the molar ratio of C272: ammonia water: strontium = 1: 0.36: 0.18, the C272 organic phase, 6.0 mol/L ammonia water and the ClSNaKBeMgCaSr/SrBaPbZnAlFe from step 2 were fractionated and extracted and the first-stage outlet water phase containing chlorine, sulfur , Strontium nitrate solution of sodium, potassium, beryllium, magnesium and calcium is added to the first stage of the saponification tank. After 8-stage co-flow saponification and phase separation, the water phase is saponification wastewater, the organic phase is strontium saponified C272 organic phase, and the saponification rate is 0.36. The obtained strontium saponified C272 organic phase is used as the extraction organic phase of step 2 for fractional distillation extraction and separation of ClSNaKBeMgCaSr/SrBaPbZnAlFe and step 3 for full-load quasi-fractionation extraction and separation of ClSNaKBeMgCa/Sr.

Step 2: Fractional extraction and separation of ClSNaKBeMgCaSr/SrBaPbZnAlFe

The organic phase of strontium saponification C272 was used as the extraction organic phase, the 2N grade strontium nitrate solution was used as the feed solution, and 3.0 mol/L HNO ₃ was used as the washing acid. The organic phase of strontium saponified C272 enters the ClSNaKBeMgCaSr/SrBaPbZnAlFe fractionation extraction system from the first stage, the 2N-grade strontium nitrate solution enters the ClSNaKBeMgCaSr/SrBaPbZnAlFe fractional distillation extraction system from the 36th stage, and the 3.0mol/L HNO ₃ washing acid enters the ClSNaKBeMgCaSr/SrBaPbZnAlFe system from the 74th stage Fractional extraction system. The strontium nitrate solution containing Cl, S, Na, K, Be, Mg and Ca was obtained from the first-stage outlet water phase of the ClSNaKBeMgCaSr/SrBaPbZnAlFe fractional distillation extraction system, which was used as the feed liquid for the full-load quasi-fractionation extraction and separation of ClSNaKBeMgCa/Sr in step 3; The organic phase loaded with strontium, barium, lead, zinc, aluminum and iron is obtained from the organic phase at the 74th stage of the ClSNaKBeMgCaSr/SrBaPbZnAlFe fractional distillation extraction system, which is used as the feed liquid for the fractional extraction and separation of Sr/BaPbZnAlFe in step 4.

Step 3: Full-load quasi-fractionation extraction and separation of ClSNaKBeMgCa/Sr

Taking the strontium saponified C272 organic phase as the extraction organic phase, the first-stage outlet aqueous phase of the ClSNaKBeMgCaSr/SrBaPbZnAlFe fractional extraction system in step 2 obtains a strontium nitrate solution containing Cl, S, Na, K, Be, Mg and Ca as the feed liquid, In step 4, the first-stage outlet water phase 6N-grade strontium nitrate solution of the Sr/BaPbZnAlFe is fractionated and extracted as a detergent. The strontium saponified C272 organic phase enters the ClSNaKBeMgCa/Sr fractionation extraction system from the 1st stage, the strontium nitrate solution containing Cl, S, Na, K, Be, Mg and Ca enters the ClSNaKBeMgCa/Sr fractionation extraction system from the 14th stage, and the 6N grade nitric acid The strontium solution enters the ClSNaKBeMgCa/Sr fractionation extraction system from the 58th stage. Aqueous nitrate solution containing chlorine, sulfur, sodium, potassium, beryllium, magnesium and calcium was obtained from the first-stage outlet aqueous phase of the ClSNaKBeMgCa/Sr fractionation extraction system for the recovery of valuable elements; from the first stage of the ClSNaKBeMgCa/Sr fractional distillation extraction system The 58-stage outlet organic phase obtains the strontium-loaded C272 organic phase, which is used as the extraction organic phase for the fractional distillation extraction and separation of Sr/BaPbZnAlFe in step 4.

Step 4: Fractional extraction and separation of Sr/BaPbZnAlFe

Taking the strontium-loaded C272 organic phase obtained from the last stage of the ClSNaKBeMgCa/Sr fractional distillation extraction system in step 3 as the extraction organic phase, and the loaded strontium barium lead zinc aluminum iron obtained in the last stage of the ClSNaKBeMgCaSr/SrBaPbZnAlFe fractional distillation extraction system in step 2 The organic phase is the feed liquid, and 3.0mol/L HNO ₃ is used to wash the acid. The organic phase of C272 loaded with strontium enters the Sr/BaPbZnAlFe fractional extraction system from the first stage, the organic phase loaded with strontium, barium, lead, zinc, aluminum and iron enters the Sr/BaPbZnAlFe fractional extraction system from the 46th stage, and the 3.0mol/L HNO ₃ washing acid is extracted from the 76th stage. into the Sr/BaPbZnAlFe fractional distillation extraction system. The target product 6N grade strontium nitrate solution was obtained from the first-stage outlet aqueous phase of the Sr/BaPbZnAlFe fractional distillation and extraction system; the C272 organic phase loaded with barium, lead, zinc, aluminum and iron was obtained from the 76th outlet organic phase of the Sr/BaPbZnAlFe fractional distillation and extraction system. Go to step 5 stripping section.

Step 5: Stripping section

The C272 organic phase loaded with barium, lead, zinc, aluminum and iron obtained from the last stage of the Sr/BaPbZnAlFe fractional distillation extraction system in step 4 enters the stripping tank from the first stage, and the _3.6mol /L HNO solution enters the stripping tank from the 12th stage. . From the first-stage outlet water phase of the stripping section, a solution containing barium, lead, zinc, aluminum and iron is obtained for the recovery of valuable elements such as lead, cadmium and zinc; the organic phase is exported from the 12th stage of the stripping section , to obtain a regenerated C272 organic phase.

The relevant element concentrations in the target product 6N grade strontium nitrate solution are: C10.0000050g/L, S0.0000020g/L, Na0.0000030g/L, K0.0000050g/L, Be0.0000080g/L, Mg0.000010g/L , Ca0.000020g/L, Sr130.0 g/L, Ba0.000020g/L, Pb0.000010g/L, Zn0.000010g/L, Al0.0000050g/L, Fe 0.0000050g/L. The product purity of the strontium nitrate solution is 99.99991%, and the yield of strontium is 92%.

Claims (4)

1. A process for preparing 6N-grade strontium nitrate is characterized by comprising the following steps: the process takes a 2N-grade strontium nitrate solution as a feed liquid and C272 as an extracting agent, and removes impurity elements of chlorine, sulfur, sodium, potassium, beryllium, magnesium, calcium, barium, lead, zinc, aluminum and iron in the 2N-grade strontium nitrate solution by extraction separation to prepare a 6N-grade strontium nitrate solution;

the method specifically comprises 5 steps: a saponification section, a fractionation extraction separation ClSNaKBeMgCaSr/SrBaPbZnAlFe, a full-load quasi-fractionation extraction separation ClSNaKBeMgCa/Sr, a fractionation extraction separation Sr/BaPbZnAlFe and a back extraction section; wherein: the extraction section for fractionating, extracting and separating the ClSNaKBeMgCaSr/SrBaPbZnAlFe realizes the separation of ClSNaKBeMgCaSr/BaPbZnAlFe, and the washing section realizes the separation of ClSNaKBeMgCa/SrBaPbZnAlFe; full-load quasi-fractionation extraction separation ClSNaKBeMgCa/Sr, fractionation extraction separation Sr/BaPbZnAlFe are directly connected in series; the outlet organic phase of the full load quasi-fractional extraction separation ClSNaKBeMgCa/Sr directly enters the 1 st stage of fractional extraction separation Sr/BaPbZnAlFe, and the 1 st stage outlet aqueous phase of the fractional extraction separation Sr/BaPbZnAlFe is used as a detergent of the full load quasi-fractional extraction separation ClSNaKBeMgCa/Sr;

step 1: saponification section

Adding a strontium nitrate solution containing chlorine, sulfur, sodium, potassium, beryllium, magnesium and calcium in an outlet water phase of the 1 st stage of a ClSNaKBeMgCaSr/SrBaPbZnAlFe fractional extraction separation system from the step 2 into the 1 st stage of a saponification tank according to the molar ratio of C272 to ammonia water to strontium of 1: 0.36: 0.18; after 8-stage co-current saponification and phase separation, the water phase is saponification wastewater, the organic phase is a strontium saponification C272 organic phase, and the saponification rate is 0.36; the obtained strontium saponification C272 organic phase is used as an extraction organic phase for fractional extraction separation of ClSNaKBeMgCaSr/SrBaPbZnAlFe in the step 2 and full-load quasi-fractional extraction separation of ClSNaKBeMgCa/Sr in the step 3;

step 2: fractional extraction separation of ClSNaKBeMgCaSr/SrBaPbZnAlFe

Using strontium saponification C272 organic phase as extraction organic phase, 2N grade strontium nitrate solution as feed liquid, 3.0mol/LHNO₃Is a washing acid; the strontium saponification C272 organic phase enters a ClSNaKBeMgCaSr/SrBaPbZnAlFe fractional extraction system from the 1 st stage, the 2N-stage strontium nitrate solution enters the ClSNaKBeMgCaSr/SrBaPbZnAlFe fractional extraction system from the feeding stage, and the concentration of the strontium nitrate solution is 3.0mol/LHNO₃Washing acid enters a ClSNaKBeMgCaSr/SrBaPbZnAlFe fractional extraction system from the last stage 1; obtaining a strontium nitrate solution containing Cl, S, Na, K, Be, Mg and Ca from the 1 st-stage outlet water phase of the ClSNaKBeMgCaSr/SrBaPbZnAlFe fractional extraction system, and using the strontium nitrate solution as a feed liquid for full-load quasi fractional extraction separation of ClSNaKBeMgCa/Sr in the step 3; obtaining a strontium barium lead zinc aluminum iron loaded organic phase from the final 1-stage outlet organic phase of the ClSNaKBeMgCaSr/SrBaPbZnAlFe fractional extraction system, and using the organic phase as a feed liquid for fractional extraction separation of Sr/BaPbZnAlFe in the step 4;

and step 3: full-load quasi-fractional extraction separation of ClSNaKBeMgCa/Sr

Taking a strontium saponification C272 organic phase as an extraction organic phase, obtaining a strontium nitrate solution containing Cl, S, Na, K, Be, Mg and Ca as a feed liquid from a 1 st-stage outlet water phase of a ClSNaKBeMgCaSr/SrBaPbZnAlFe fractional extraction system in the step 2, and taking a 1 st-stage outlet water phase 6N-stage strontium nitrate solution for fractional extraction separation of Sr/BaPbZnAlFe as a detergent in the step 4; the strontium saponification C272 organic phase enters a ClSNaKBeMgCa/Sr fractionation extraction system from the 1 st level, a strontium nitrate solution containing Cl, S, Na, K, Be, Mg and Ca enters the ClSNaKBeMgCa/Sr fractionation extraction system from a feeding level, and a 6N-level strontium nitrate solution enters the ClSNaKBeMgCa/Sr fractionation extraction system from the last 1 level; obtaining a nitrate aqueous solution containing chlorine, sulfur, sodium, potassium, beryllium, magnesium and calcium from a 1 st stage outlet water phase of a ClSNaKBeMgCa/Sr fractional extraction system; obtaining a C272 organic phase loaded with strontium from the last 1-stage outlet organic phase of the ClSNaKBeMgCa/Sr fractional extraction system, and using the C272 organic phase as an extraction organic phase for fractional extraction and separation of Sr/BaPbZnAlFe in the step 4;

and 4, step 4: fractional extraction separation of Sr/BaPbZnAlFe

Fractionation of the end of the extraction system with ClSNaKBeMgCa/Sr from step 3The C272 organic phase loaded with strontium obtained at the 1 stage is an extraction organic phase, the last 1 stage loaded with strontium barium lead zinc aluminum iron obtained at the ClSNaKBeMgCaSr/SrBaPbZnAlFe fractional extraction system of the step 2 is a feed liquid, and the concentration of the feed liquid is 3.0mol/LHNO₃Washing with an acid; the strontium-loaded C272 organic phase enters a Sr/BaPbZnAlFe fractional extraction system from the 1 st stage, and the strontium-barium-lead-zinc-aluminum-iron-loaded organic phase enters the Sr/BaPbZnAlFe fractional extraction system from the feeding stage and has the concentration of 3.0mol/LHNO₃Washing acid enters a Sr/BaPbZnAlFe fractional extraction system from the last level 1; obtaining a target product of 6N-grade strontium nitrate solution from a 1 st-grade outlet water phase of the Sr/BaPbZnAlFe fractional extraction system; obtaining a C272 organic phase loaded with barium, lead, zinc, aluminum and iron from the last 1-stage outlet organic phase of the Sr/BaPbZnAlFe fractional extraction system, and completely entering a back extraction section in the step 5;

and 5: stripping section

The C272 organic phase loaded with barium, lead, zinc, aluminum and iron obtained from the last stage 1 of the Sr/BaPbZnAlFe fractional extraction system from the step 4 enters a stripping tank from the stage 1, and 3.6mol/LHNO₃The solution enters a stripping tank from the 12 th stage; obtaining a solution containing barium, lead, zinc, aluminum and iron from a 1 st stage outlet water phase of the back extraction section; the organic phase is discharged from the 12 th stage of the stripping section to obtain a regenerated C272 organic phase.

2. The process for preparing 6N grade strontium nitrate according to claim 1, wherein: the C272 organic phase is a sulfonated kerosene solution of C272, wherein the concentration of the C272 is 1.0 mol/L.

3. The process for preparing 6N grade strontium nitrate according to claim 1, wherein: the concentration of related elements in the 2N-grade strontium nitrate solution is respectively as follows: C10.0010g/L-0.0050 g/L, S0.0010g/L-0.010 g/L, Na0.010g/L-0.030 g/L, K0.0010g/L-0.0050 g/L, Be0.010g/L-0.020 g/L, Mg0.010g/L-0.050 g/L, Ca0.050g/L-0.30 g/L, Sr110.0g/L-150.0 g/L, Ba0.050g/L-0.20 g/L, Pb0.0010g/L-0.0050 g/L, Zn0.0010g/L-0.0050 g/L, Al0.010g/L-0.030 g/L, Fe0.010g/L-0.030 g/L.

4. The process for preparing 6N grade strontium nitrate according to claim 1, wherein: the concentration of related elements in the 6N-grade strontium nitrate solution is respectively as follows: C10.0000010g/L-0.0000050 g/L, S0.0000010g/L-0.0000020 g/L, Na0.0000010g/L-0.0000030 g/L, K0.0000010g/L-0.0000050 g/L, Be0.0000020g/L-0.0000080 g/L, Mg0.0000040g/L-0.000010 g/L, Ca0.0000050g/L-0.000020 g/L, Sr130.0g/L-140.0 g/L, Ba0.0000050g/L-0.000020 g/L, Pb0.0000030g/L-0.000010 g/L, Zn0.0000010g/L-0.000010 g/L, Al0.0000010g/L-0.0000050 g/L, Fe0.0000010g/L-0.0000050 g/L.

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